Shaker drive



Dec. 23,- 1958 v c. D. FISHER KSHAKER DRivE Filed Aug. 29, 195e M M IILn n.l f n M/ M r .IV HF! ,...4 -LBIIL fa .b

United States Patent O f 2,865,216 SHAKER DRIVE Chester Donald Fisher,Muncy, Pa., assignor to Sprout, Waldron & Company, Inc., Muucy, Pa., acorporation of Pennsylvania Application August 29, 1956, Serial No.606,846

8 Claims. (Cl. 74-61) This invention relates to an oscillating shakerdrive for imparting oscillating or vibrating motion to a shaker or likedevice and, more particularly, to an eccentric shaker drive adapted toimpart vibrational or oscillating force in one plane without substantialvibration components in other planes.

f Apparatus such as shakers of various sorts, sieves, screens forseparating solid materials according to particle size, sluice boxes andthe like are conventionally equipped with a drive mechanism which willShake them or vibrate them to increase or control or enhance the flow ofmaterial therethrough. As such apparatus to be vibrated increases insize, however, it may be found that applying a conventional electricalvibrator or a conventional mechanical vibrating drive, such as a shaftwith eccentric weights thereon, may produce objectionable components ofvibration in the whole apparatus in addition to the desired shaking orvibrating of the desired portion of the apparatus.

Thus, considering a substantially flat screen or sieve which it isdesired to vibrate predominately in a horizontal plane, the applicationthereto of conventional eccentric-type vibrating or oscillating rams ordrives may also produce substantial vertical vibrational components inaddition to the desired horizontal oscillation, and such verticalvibrating components may be objectionable and are wasteful.

According to this invention, however, a rotating vibrating drive isprovided having two counter-rotating eccentrically weighted pulleyswhich produce the desired oscillating or vibrating movement but are soconstructed and timed that substantially all the oscillating orvibrating force is applied in only one plane with only minor, if any,moments of force or vibration effects being generated by the drive inother planes.

One object of this invention is to provide a vibratory motion drivemechanism of the character described in which substantially all of thedrive force is generated in but one plane and having two coaxialcounter-rotating eccentrically weighted pulleys driven with a positivetiming belt.

Another object of this invention is to provide a drive of the characterdescribed in which two eccentrically Weighted counter-rotated pulleysare mounted on a common shaft and are po-sitively driven in timedrelation with each other to effect continuously controlled positioningof the eccentric weights thereon with respect to each other.

A further object of this invention is to provide a drive of thecharacter described which may be beltdriven and open for accessibilityand which 'is free of gear train drives or the necessity of beingenclosed in an oil tight casing.

Other objects and advantages of this invention will be apparent from thefollowing description, the accompanying drawing, and the appendedclaims.

In the drawing- Fig. 1 is a plan view of a vibratory motion drive em-2,865,210 Patented Dec. 23, 1958 ICC bodying this invention as appliedto a classifying screen device for solid particles;

Fig. 2 is a plan end view of the device illustrated in Fig. 1;

Fig. 3 is a diagrammatic view showing various positions of the eccentricweights during the operation of a device embodying this invention;

Fig. 4 is a transverse section through a device embodying the inventionalong the line 4-4 of Fig. l; and

Fig. 5 is a fragmentary section along the line 5 5 of Fig. 4.

Referring to the drawing, in which like characters of reference refer tolike parts throughout the several views thereof, a classifying screenfor classifying solid particles according to size is fragmentarilyillustrated at 10 at being flexibly mounted in known manner in asupporting framework 11 for substantially free endwise movement along asubstantially horizontal plane within the framework 11. At one end ofscreen 10 is mounted a U-shaped bracket 12 carrying a tixed shaft 13.Freely rotatable around shaft 13 are two hollow pulleys 15 and 16,mounted for rotation about shaft 13 as by bearings 17.

The outer peripheries of pulleys 15 and 16 are toothed, asV

indicated by the teeth 19, to accommodate the internal rib 2Q of anendless timing belt 25 which runs, as shown, over both pulleys 15 and16, around a drive pulley 26 driven by a motor 27 and around an idlingpulley 28.

As will be apparent from the foregoing, the internal ribs 20 on drivebelt 25 engage in the teeth 19 on pulleys 15 and 16. Thus with the beltthreaded as shown in the drawing, pulleys 15 and 16 will be positivelydriven at the same speed but in opposite directions and in continuallymaintained timed relation with each other.

Pulleys 26 and 28 need be merely flat pulleys acting on belt 25 since apositive guarantee against slippage of the belt around these pulleys isof little consequence provided the exact timed relative positioning ofpulleys 15 and 16 With respect to each other is maintained.

Pulleys 15 and 16 contain fastened therein at one point around theperiphery thereof heavy weights 30 and 31, each eccentrically arrangedwithin its respective pulley and each of sufficient size and mass withrespect to the size and mass of pulleys v15 and 16 to give a substantialunbalanced force as the pulleys are rotated.

In the operation of the device, the toothed pulleys are set with respectto each other by timing belt 25 so that, during continuedcounter-rotation of pulleys 15 and 16, the weights 30 and 31 thereinmeet or come face to face or pass each other at the horizontalcenterline of the device, but are diametrically opposite as they passthe vertical centerline of the device. This sequence of conditions isillustrated diagrammatically in Fig. 3 where weight 31 is shown in fullline infour sequential positions while weight 30 is shown in dottedlines in the positions it assumes at the same movements of time thatpulley 31 is in the positions shown for it.

Fromvthe foregoing, it will be noted that the meeting or passing of botheccentric weights 30 and 31 (each time each one passes the horizontalcenterline of the device) will give an impact or moment of force alongthe horizontal centerline, the direction of this force depending uponwhich side of the vertical centerline the meeting of the weights 30 and31 occurs. When pulleys 15 and 16, on the other hand, are rotated sothat the weights 30 and 31 are passing the vertical centerline of thedevice, the weights will be diametrically opposed and substantially inbalance with each other with no substantial moment of force along thevertical centerline, and the two weights will remain substantially inbalance and each counteracting the vibrational force of the other exceptadjacent the horizontal centerline where the cen,-

trifugal force acting on each of the eccentric weights 30 and 31 willcooperate toproduce'a substantial oscillatory force along thehorizo-ntal plane.

In this manner, accordingly, considerable vibration or oscillation canbe imparted to screen primarily along a horizontal plane without alsoimparting substantial vertical components of vibratory force to thesupporting framework 11. It should also be noted that, because of thebelt drive, motor 27- can-be-mounted onframe 11, rather than on themovingscreen 10, despite continued movement of the screen and bracket 12and pulleys 15 and 16 with respect to frame 11 and motor 27.Furthermore, both pulleys and 16 are concentrically mounted on a commonshaft so that the counterbalancing of the weights 30 and 31 at thevertical centerline and the cooperative unbalancing of the Weights 30and 31 when they pass the horizontal centerline are enhanced as comparedto a case where pulleys 15 and 16 were not concentrically'mounted on acommon shaft. Also, the absence of a gear drive for effecting the timedpositive counter-rotation of pulleys 1S and 16 means that there is noparticular need for a gear box or other oil-tight casing to enclose thedevice nor of jack shafts or other extra parts.

It will accordingly be seen that this device provides asimple, readilyaccessible, and economical means for producing oscillatory orvibrational motion in one plane while avoiding vibrational components inother planes. As will be apparent from the foregoing, it makes little orno difference as to in which plane it is desired for the driving motionto occur since whether the oscillating or vibratory motion produced bythis device acts in a horizontal plane or in a vertical plane or in anyother plane depends merely upon the initial setting of pulleys 15 and 16with respect to each other by belt 25 so as to determine at what pointweights 30 and 31 will be adjacenteach other and at which points duringrotation they will be diametrically opposed and in balance.

While the forms of apparatus herein described constitute a preferredembodiment of the invention, it is to be understood that the inventionis not limited to these precise methods or forms of apparatus, and thatchanges may be made therein without departing from the scope of theinvention which is defined in the appended claims.

What is claimed is:

l. An oscillating drive device of the character described for impartingoscillatory motion to apparatus along substantially only a single plane,comprising a pair of coaxial pulleys, means for mounting said pulleysfor counter-rotation on said apparatus, an eccentric weight ofsubstantial mass on each of said pulleys, an endless positive drivetiming belt for positive engagement with said pulleys, means for drivingsaid belt, and means for threading said belt for counter-rotation ofsaid pulleys with respect to each other.

2. An oscillating drive device of the character described for impartingoscillatory motion to apparatus along substantially only a single plane,comprising a pair of coaxial pulleys, means for mounting said pulleysfor counter-rotation on said apparatus, an eccentric weight ofsubstantial mass on each of said pulleys, a positive drive timing beltfor positive engagement with said pulleys, means for driving said belt,and means for threading said belt for counter-rotation of said pulleyswith respect to each other, said belt being threaded over said pulleysto time said counter-rotation thereof effecting meeting of saideccentric weights in said single plane and separation of said eccentricweights in other planes.

3. An oscillating drive device of the character described for impartingoscillatory motion to apparatus along substantially only a single plane,comprising a pair of coaxial pulleys, means for mounting said pulleysfor counter-rotation on said apparatus, an eccentric weight ofsubstantial mass on each of said pulleys, the outer edges of saidpulleys being toothed, a positive drive-timingbelt hav-- ing ribs on theinner surface thereof for engaging said mtoothedv pulleys, means fordriving said belt, and means for threading said belt forcounter-rotation of said pulleys with respect to each other.

4. An oscillating drive device of the character described for impartingoscillatory motion to apparatus along substantially only a single plane,comprising a pair of coaxial pulleys, means for mounting said pulleysfor counter-rotation on said apparatus, an eccentric weight ofsubstantial mass on each of said pulleys, the outer edges of saidpulleys being toothed, a positive drive timing belt having ribs on theinner surface thereof for engaging said toothed pulleys, means fordriving said belt, and means for threading said belt fo-rcounter-rotation of said pulleys with respect to eachother, said beltbeing threaded over said pulleys to time said counter-rotation thereofeffecting meeting of said eccentric weights in said single plane andseparation of said eccentric weights in other planes.

5. An oscillating drive device of the character described for impartingoscillatory motion to apparatus along substantially only a single plane,comprising a pair of coaxial pulleys each of which is eccentricallyunbalanced, means for mounting said pulleys for counter-rotation on saidapparatus, a positive drive timing belt for positive engaging and timingsaid pulleys, means for driving said belt, and means for threading saidbelt for counter-rotation of said pulleys with respect to each other,said belt being threaded over said pulleys totime said counter-rotationthereof effecting joining of said unbalancing in said single plane andoffsetting of said unbalancing in other planes.

6. In an oscillating drive of the character described for impartingoscillating motion to apparatus to be oscillated in substantially but asingle plane, the combination which comprises a pair of counter-rotatingeccentrically weighted pulleys, means for mounting said pulleys forrotation in face to face relation on said apparatus to be oscillated, apositive drive belt for positive engagement with said pulleys, a drivepulley for driving said belt, means for mounting said drive pulley on aportion of said apparatus which is stationary and not oscillating, meansfor threading said drive belt over said eccentrically weighted pulleysand said drive pulley for continuous counter-rotational driving of saideccentrically weighted pulleys, and said eccentrically weighted pulleysbeing angularly positioned with respect to each other so that saideccentric weights thereof meet during counter-rotation of said pulleysonly in said plane in which said apparatus is oscillated.

7. In an oscillating drive of the character described for impartingoscillating motion to apparatus to be oscillated in substantially but asingle plane, the combination which comprises a pair of counter-rotatingeccentrically weighted pulleys, means for mounting said pulleys forrotation in face to face relation on a common shaft on said apparatus tobe oscillated, an endless positive gripping drive belt for positiveengagement with said pulleys, a drive pulley for driving said drivebelt, an 'idler pulley for engaging said drive belt and spaced from saiddrive pulley, means for mounting said drivepulley and said idler pulleyon a portion of said apparatus which is stationary and not oscillating,said drive belt being threaded over said eccentrically weighted pulleysand between said drive pulley and said idler pulley for Continuouscounter-rotational driving of said eccentrically weighted pulleys andsaid eccentrically Weighted pulleys being angularly positioned withrespect to each other so that said eccentric weights thereof meet duringcounter-rotation of said pulleys only in said plane in which saidapparatus is oscillated.

8. ln an oscillating drive of the character described for impartingoscillating motion to apparatus to be oscillated in substantially but asingle plane, the combination which comprises a pair ofcounter-rotating:eccentrically weghted=pulleys, -m'eans' formountingsaid rpulleys vfor rotation in face to face relation on saidapparatus to be oscillated, the outer periphery of said pulleys beingtoothed, a positive gripping drive belt, said belt having ribs on theinner surface thereof for positive engagement with said toothed surfacesof said pulleys, a drive pulley for driving said drive belt, an idlerpulley for engaging said drive belt and spaced from said drive pulley,means for mounting said drive pulley and said idler pulley on saidapparatus, said drive belt being threaded over said eccentricallyweighted pulleys and between said drive pulley and said idler pulley forcontinuous counter rotational driving of said eccentrically weightedpulleys 6 and said eccentrically weighted pulleys being angularlypositioned withl respect to each other so that said eccentric weightsthereof meet during counter-rotation of said pulleys only in said planein which said apparatus is oscillated.

References Cited in the le of this patent UNITED STATES PATENTS1,828,136 Freedlander Oct. 20, 1931 1,943,220 Keefer Jan. 9, 19342,065,798 Dempsey Dec. 29, 1936 2,511,885 Thompson June 20, 1950

